<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<!--数据代理，通过一个对象代理对另一个对象中属性的操作（读写）-->
<script type="text/javascript">
    let obj = {x:100}
    let obj2 = {y:200}
    Object.defineProperty(obj2,'x',{
        get() {
            return obj.x
        },
        set(v) {
            obj.x = v
        }

    })
</script>
</body>
</html>